The present invention relates to devices for recycling engine exhaust gas to reduce noxious exhaust emissions. The exhaust gas discharged out of various engines, e.g., gasoline and diesel automobile engines, can be fed into an exhaust gas molecule dissociating tube for separating the chemical substances contained in the exhaust gas into molecules. If the exhaust gas is also fed through an electrostatic filter for dedusting, the purified and dissociated exhaust gas can be returned to the combustion chamber of the engine without discharging the exhaust gas outside. This makes the maximum use of the oxygen produced by decomposing oxygen compounds contained in the exhaust gas which releases oxygen ions.
So far, total recycling of engine exhaust gas has not been available. Exhaust gas discharged from conventional automobile engines is often released into the atmosphere, as it is through a conventional muffler. In some devices a mixture of dedusted exhaust and clear air has been drawn into the engine to increase the combustion efficiency of the engine and thereby release an exhaust gas containing fewer noxious substances into the atmosphere, as shown in U.S. Pat. Nos. 3,035,561 and 4,326,862, but these achieve only partial recycling.
There has also been a so-called engine exhaust gas recirculation system which sucks up and recirculates a part of the exhaust gas back to the engine through a detector regulator valve requiring an intricate detecting device for the purpose of decreasing nitrogen oxides (NO.sub.x) contained in the exhaust gas.
These prior art devices have all been such that exhaust gas is released in the atmosphere. Even emission control devices equipped with an electrostatic filter have encountered difficulty in purifying the exhaust gas, and they release exhaust gases containing noxious substances into the atmosphere. Thus, unless more than an electrostatic filter is provided and more than partial recycling is achieved, an exhaust gas containing a considerable amount of noxious substances will be released into the atmosphere. Furthermore, if the engine exhaust gas recirculating system requires a special detector/regulator valve, that raises the price of the system, naturally, and even then because a part of exhaust gas is still released in the atmosphere, the problems of environmental pollution including the air pollution, emission of carcinogenic substances, etc. remain unsolved.
The present invention has been made to overcome the disadvantages inherent in the above-mentioned prior art devices. The present invention provides a novel device for totally recycling engine exhaust gas, wherein exhaust gas discharged out of the engine is dedusted by means of an electrostatic filter and also dissociated into monomolecules, e.g., oxygen and carbon, and refed into the engine to avoid release of noxious material into the atmosphere, as well as to make the best use of the oxygen contained in the exhaust gas.